Favorite cartoon/video game villian?

[Samael]

Little known character from the little known "Galaxy Rangers" cartoon.

I liked the show because it dealt relatively mature with themes like slavery, death and such.
Didn't hurt that it had a kickass rock soundtrack

Scarecrow

The Scarecrow is an ancient, powerful alien monstrosity created for a long-ago war between the (then) technologically advanced Tarkon and a now-forgotten enemy. Even though the war is thousands of years over, he still is primarily motivated to destroy the living, ancient machine.

Upon defeat, it was forced into hibernation for uncounted millennia under the surface of the planet Granna (he mentions the figure "a hundred million years" but this could be an exaggeration). The entity was disturbed; forcibly awakened by a Kiwi agricultural analysis device whose rumbling thumpings stirred the creature back into consciousness. Scarecrow sustains himself by draining, fatally, the life force of others. His first victims were a sheriff and deputy sent out on patrol from the colony, followed by one of the colonists. Niko almost became another of his victims, but Goose was able to track him to a farmhouse. It was here that Goose gave the entity the moniker "Scarecrow," named after a ghost story he heard from the locals. During the fight, the house caught fire, and Scarecrow was trapped inside while Goose and Zozo managed to flee. The Scarecrow was seen fleeing the burning house covered in flames and cackling maniacally.

Later appearances placed him draining entire Tarkonian villages of their lifeforce in an attempt to gain enough power to kill the Heart of Tarkon (another ancient weapon which could destroy him) ("Scarecrow's Revenge") and crashlanding on Mesa ("Aces and Apes"). In the final episode of the series, he infiltrates the Tarkonian court, exerting a powerful mental control over the court until Doc, Princess Maya, King Spartos, and the court Shaman reactivate the Heart and the defenses of the planet. The Heart dispatched the Scarecrow, but we can never know for sure if that was indeed the end of the hard-to-kill foe.

[Slaven]

I am sorry I forgot this.

Beast Wars: Megatron 'Yes' Compilation.

Dinobot and Waspinator = best villains ever.

[AmberTrash]

Like some others have posted, Kefka from FF6 takes the cake for me, at least for video games. The outfit and laugh would be enough for me, but the motiveless eradication of all life is a nifty thing as well. Really though, it's mostly the outfit.

[AeonReflux]

SEPHIROTH.

His introduction alone is fascinating... I am actually considering naming one of my children after him.

[Oniya]

Please don't.  Remember what happened to his parents.

[AeonReflux]

point taken. My next child will then be named after my second favorite villain, Dr. Doofenshmirtz.

[Type70item]

I would have to agree with AeonReflux in saying Sephiroth, tied with Magus from Chrono Trigger, and Kefka from Final Fantasy VI (just because he was such a strange little guy)

[Sabby]

Not sure many would agree with me here, but... Gary, from Bully.

He's such an underrated villain :/ He's like The Joker, only a much more subtle level of crazy. Joker will tell the whole city a Hospital will explode unless they devolve into animals for his amusement, where as Gary will sow the seeds, slowly, tend his crop, and then sit back and watch as the chaos blooms, and you'd never know it was him, unless you directly confronted him. He doesn't need the recognition for his deeds, he does this for himself, and he fucking loves it.

[Andalon]

Aaaah, Scarecrow... funny. I watched that episode (again) just yesterday

Hm, my fav... Nemesis from Sabre Rider. Truely an evil genius, and refreshingly ruthless and brutal.